1 use crate::utils::{match_def_path, span_lint_and_sugg};
2 use if_chain::if_chain;
4 use rustc::hir::def::Def;
5 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
6 use rustc::{declare_tool_lint, lint_array};
7 use rustc_errors::Applicability;
9 /// **What it does:** Checks for usage of `ATOMIC_X_INIT`, `ONCE_INIT`, and
12 /// **Why is this bad?** `const fn`s exist
14 /// **Known problems:** None.
18 /// static FOO: AtomicIsize = ATOMIC_ISIZE_INIT;
24 /// static FOO: AtomicIsize = AtomicIsize::new(0);
26 declare_clippy_lint! {
29 "Lint usages of standard library `const`s that could be replaced by `const fn`s"
32 pub struct ReplaceConsts;
34 impl LintPass for ReplaceConsts {
35 fn get_lints(&self) -> LintArray {
36 lint_array!(REPLACE_CONSTS)
40 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ReplaceConsts {
41 fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
43 if let hir::ExprKind::Path(ref qp) = expr.node;
44 if let Def::Const(def_id) = cx.tables.qpath_def(qp, expr.hir_id);
46 for &(const_path, repl_snip) in REPLACEMENTS {
47 if match_def_path(cx.tcx, def_id, const_path) {
52 &format!("using `{}`", const_path.last().expect("empty path")),
54 repl_snip.to_string(),
55 Applicability::MachineApplicable,
65 const REPLACEMENTS: &[(&[&str], &str)] = &[
67 (&["core", "sync", "ONCE_INIT"], "Once::new()"),
70 &["core", "sync", "atomic", "ATOMIC_BOOL_INIT"],
71 "AtomicBool::new(false)",
73 (&["core", "sync", "atomic", "ATOMIC_ISIZE_INIT"], "AtomicIsize::new(0)"),
74 (&["core", "sync", "atomic", "ATOMIC_I8_INIT"], "AtomicI8::new(0)"),
75 (&["core", "sync", "atomic", "ATOMIC_I16_INIT"], "AtomicI16::new(0)"),
76 (&["core", "sync", "atomic", "ATOMIC_I32_INIT"], "AtomicI32::new(0)"),
77 (&["core", "sync", "atomic", "ATOMIC_I64_INIT"], "AtomicI64::new(0)"),
78 (&["core", "sync", "atomic", "ATOMIC_USIZE_INIT"], "AtomicUsize::new(0)"),
79 (&["core", "sync", "atomic", "ATOMIC_U8_INIT"], "AtomicU8::new(0)"),
80 (&["core", "sync", "atomic", "ATOMIC_U16_INIT"], "AtomicU16::new(0)"),
81 (&["core", "sync", "atomic", "ATOMIC_U32_INIT"], "AtomicU32::new(0)"),
82 (&["core", "sync", "atomic", "ATOMIC_U64_INIT"], "AtomicU64::new(0)"),
84 (&["core", "isize", "MIN"], "isize::min_value()"),
85 (&["core", "i8", "MIN"], "i8::min_value()"),
86 (&["core", "i16", "MIN"], "i16::min_value()"),
87 (&["core", "i32", "MIN"], "i32::min_value()"),
88 (&["core", "i64", "MIN"], "i64::min_value()"),
89 (&["core", "i128", "MIN"], "i128::min_value()"),
90 (&["core", "usize", "MIN"], "usize::min_value()"),
91 (&["core", "u8", "MIN"], "u8::min_value()"),
92 (&["core", "u16", "MIN"], "u16::min_value()"),
93 (&["core", "u32", "MIN"], "u32::min_value()"),
94 (&["core", "u64", "MIN"], "u64::min_value()"),
95 (&["core", "u128", "MIN"], "u128::min_value()"),
97 (&["core", "isize", "MAX"], "isize::max_value()"),
98 (&["core", "i8", "MAX"], "i8::max_value()"),
99 (&["core", "i16", "MAX"], "i16::max_value()"),
100 (&["core", "i32", "MAX"], "i32::max_value()"),
101 (&["core", "i64", "MAX"], "i64::max_value()"),
102 (&["core", "i128", "MAX"], "i128::max_value()"),
103 (&["core", "usize", "MAX"], "usize::max_value()"),
104 (&["core", "u8", "MAX"], "u8::max_value()"),
105 (&["core", "u16", "MAX"], "u16::max_value()"),
106 (&["core", "u32", "MAX"], "u32::max_value()"),
107 (&["core", "u64", "MAX"], "u64::max_value()"),
108 (&["core", "u128", "MAX"], "u128::max_value()"),